Seven boys with primary enuresis were measured by 62 all-night EEGs, during which time 48 wets occurred. Imipramine was administered in a placebo, drug cross-over manner. Subjects with predominantly arousal enuresis showed increased evidence of neuroticism, a history of sporadic wetting, and no family history of enuresis. Subjects with predominantly nonarousal enuresis had minimal evidence of maladjustment, a history of regular wetting, family history of enuresis, and a better response to imipramine. The authors formulate a somatopsychic model for the etiology of enuresis, hypothesizing a pathophysiological substrate to explain the phenomenon.Abstract Teaser